7 Electrical Estimating Mistakes That Quietly Kill Your Profit

Nobody loses money on a quote on purpose. It happens quietly, the same handful of mistakes, made on job after job, each one shaving a little off the margin until there’s nothing left.

The good news is they’re the same seven mistakes nearly every time. Fix these and most of the leak stops.

1. Underestimating labour

The big one. The job that “should’ve been a day” turns into two, and the quote only had a day in it. Materials you can count. Labour you guess, and the guess is almost always too low.

The fix: stop guessing whole-job hours. Break the work into tasks, rough-in, fit-off, terminations, testing, and time each one. There’s a full method in how to estimate labour hours.

2. Forgetting overhead

This is the number one reason sparkies underbid. Your business has costs that exist whether you’re on a job or not, vehicle, insurance, software, phone, admin. If that overhead isn’t built into the quote, it comes out of your pocket.

The fix: load 12-18% overhead into every job, every time. See why electricians undercharge for how deep this one runs.

3. Missing scope and line items

A forgotten downlight. Conduit you under-counted. The bit of make-good you didn’t think about. Individually small, but they compound across every quote you write.

The fix: quote materials by system, lighting, power, data, so nothing hides in a lump sum. The complete quote checklist covers the full list.

4. Leaving out travel and setup

Travel, loading the van, setup, pack-down, cleanup. None of it turns a screw, all of it is paid time. It’s the most commonly forgotten labour in the whole estimate.

The fix: add a travel and setup line to every quote as standard. Make it automatic.

5. Forgetting permits, testing and certification

You quote the install and forget the regulatory step you’re legally required to do. Testing and certification is mandatory, chargeable work, not a freebie you throw in.

The fix: itemise testing and cert as its own line. It’s compliance, and it gets paid for.

6. No allowance for variations

“While you’re here, can you just…” Yes you can, and if it never makes it onto the invoice you just worked for free. Variations are where margin disappears most quietly.

The fix: log every variation the moment it happens and get it agreed in writing. Handling variations covers how to do it cleanly.

7. Confusing markup with margin

The most expensive maths mistake in the trade. You add 30% to your cost, think you’re on 30% margin, and you’re actually on 23%. Do that across hundreds of quotes a year and the gap is enormous.

The fix: set a target margin and work the price back with Sell = Cost ÷ (1 − margin). Run a real job through the Markup Calculator and the difference will sting.

See what it’s costing you

These seven aren’t dramatic. That’s why they survive. Each one feels too small to chase, and together they’re the difference between a business that pays you properly and one that just keeps you busy.

Run a year’s work through the Profit Leak Calculator and you’ll see the total. Most sparkies are quietly shocked.

You don’t lose a business to one big mistake. You lose it to seven small ones, repeated.